Cosmic rays in galactic and extragalactic magnetic fields

Abstract

We briefly review sources of cosmic rays, their composition and spectra as
well as their propagation in the galactic and extragalactic magnetic fields,
both regular and fluctuating. A special attention is paid to the recent results
of the X-ray and gamma-ray observations that shed light on the origin of the
galactic cosmic rays and the challenging results of Pierre Auger Observatory on
the ultra high energy cosmic rays. The perspectives of both high energy
astrophysics and cosmic-ray astronomy to identify the sources of ultra high
energy cosmic rays, the mechanisms of particle acceleration, to measure the
intergalactic radiation fields and to reveal the structure of magnetic fields
of very different scales are outlined.Comment: 42 pages, Space Science Review